what is the surface area of this square pyramid with a base length of 4 centimeters and slant height of 9 centimeters? HELP PLEASE!!!!

Answer:
The surface area of a square pyramid = 1/2 * slant height * base perimeter + area of base
The slant height is 8 cm
The base perimeter is 4 * 5 cm = 20 cm
The area of the base is 5 cm * 5 cm = 25 cm**2
Plugging into the formula the area =
1/2 * 8 cm * 20 cm + 25 cm**2 =
4 cm * 20 cm + 25 cm**2 =
80 cm**2 + 25 cm**2 = 105 cm**2